Process for the preparation of mixtures of isometric substituted phthalocyanines

ABSTRACT

Mixtures of isomeric substituted phthalocyanines, and process for their preparation Mixtures of four α-alkoxy-substituted phthalocyanine isomers, predominantly ##STR1## or of four β-alkoxy-substituted phthalocyanine isomers, where 
     Me is a divalent metal atom or a divalent oxo metal, 
     R 1  is a linear or branched C 1  --C 16  alkyl, C 3  --C 16  alkenyl or C 3  --C 16  alkynyl radical which is unsubstituted or substituted by C 1  --C 12  alkoxy, --CN, NO 2 , halogen, --OH, phenyl, cyanophenyl, nitrophenyl, halophenyl, hydroxyphenyl or (C 1  --C 12  alkoxy)phenyl, 
     wherein two isomers of the formula II and of the formula III make up at least 80% of the total mixture and the two other isomers make up at most 20% of the total mixture, with the ratio between the compounds of the formula II and the compounds of the formula III being from 0.3 to 3.0: 1. 
     The isomer mixtures can be obtained by reacting α- or β-alkoxyphthalodinitriles in the presence of a metal salt, a Lewis acid, a nitroaromatic compound as solvent and at least equimolar amounts of urea, based on the phthalodinitrile.

This application is a continuation of patent application Ser. No.08/529,822, filed on Sep. 8, 1995, now U.S. Pat. No. 5,663,326.

The invention relates to a mixture of isomeric alkoxy-substitutedphthalocyanines and to a process for their preparation by reactingcompounds of the formula V ##STR2## in the presence of a metal salt, aLewis acid, urea and selected solvents.

The use of dyes which absorb radiation in the near infra-red (NIR)region for recording information in WORM (write once read many) systemshas been known for some time and is described, for example, by M.Emmelius et al. in Angewandte Chemie, Issue 11, pages 1475-1502 (1989).The change in absorption which is necessary for recording information inthe form of bits can be achieved by physical changes (for example bysublimation or diffusion) or by chemical changes (for examplephotochromicity, isomerization or thermal decomposition) by laserirradiation in such recording materials.

Substituted phthalocyanines are an important class of dyes for use insuch WORM systems, since they can have a high NIR absorption in theregion from 700 to 900 nm if they have appropriate peripheralsubstitution, depending on the central metal atom. In addition to theabsorption properties, their solubility in organic solvents, especiallyaliphatic hydrocarbons, is of great importance, since the absorptionlayer of optical storage materials is frequently produced in aspin-coating process from an organic solvent.

EP-A-337 209 describes polysubstituted alkylphthalocyanines which can beobtained by reacting substituted phthalodinitriles in high-boilingsolvents in the presence of a Lewis acid. The solvents proposed areurea, chloronaphthalene, nitrobenzene, alcohols and amino alcohols. Thereaction temperature can be, for example, 250° C. The solubility of theresultant alkylphthalocyanines in organic solvents and the compositionof the reaction product are not described.

The preparation of alkoxy-substituted phthalocyanines is likewise known,and the isomeric tetraisopropoxyphthalocyanines are described in NouveauJournal de Chemie, Vol. 6, pp. 653-658 (1982). The reaction is carriedout, for example, on polymer-bonded phthalodinitrile and gives a pureisomer. If the reaction is carried out at elevated temperature indimethylaminoethanol without polymer bonding, an isomer mixture ofunknown distribution is formed.

Another process for the preparation of α-alkoxy-substitutedphthalocyanines is described, for example, in EP-A-0 373 643 and EP-A-0492 508. EP-A-0 373 643 describes the formation of a single symmetricalisomer on heating a mixture of α-alkoxyphthalodinitrile, metal salt,base and alcohol to reflux. In EP-A-0 492 508, by contrast,α-alkoxyphthalodinitrile and an organic base are heated in an alcohol to90°-120° C. and a metal salt is added at this temperature, giving, asmain products, 2 positional isomers in a ratio of from 40:60 to 60:40,of which one is readily soluble and the other less soluble in organicsolvents. An alternative given in EP-A-0 492 508 is to use thecorresponding diiminoisoindoline. By varying the addition of base andthe temperature, the isomer ratio can be modified. In each case 2isomers are formed, of which the m ore highly soluble is in an excess offrom 85-95 parts to 5-15 parts. This process variant has thedisadvantage that the diiminoisoindoline must be prepared first, meaningthat a further reaction step is necessary. Furthermore, both thevariants described in EP-A-0 492 508 give predominantly only two of the4 possible isomers, and only one of the two more highly soluble, whichhas an adverse effect on the association and crystallization behaviour.

In general, a mixture of a plurality of readily soluble isomers has alower tendency toward association and crystallization than one in whicha single isomer predominates or in which significant amounts (forexample ≧10%) of low-solubility isomers are present.

The present invention relates to a readily soluble isomer mixturepredominantly comprising two readily soluble positional isomers ofalkoxy-substituted phthalocyanines, and to a process in which a) goodyields are obtained and b) asymmetrical positional isomers are formedpreferentially, thus achieving good solubility of the α- orβ-alkoxy-substituted phthalocyanines in organic solvents. The isomermixtures can also serve as intermediates for further reactions. Thus,for example, as described in EP-A-0 513 370, they can be reacted withhalogen to give the corresponding halogenated alkoxyphthalocyanines,where a multiplicity of isomers can be formed, which is advantageous forthe solubility and shelf life of the solution. In these halogenatedisomer mixtures of phthalocyanines, halogen can furthermore be replacedby at least one phosphorus substituent, which allows the polarity of thecompounds and thus their solubility to be matched to a wide variety ofsolvents.

The invention relates to a mixture of isomeric α-alkoxy-substitutedphthalocyanines of the formulae I-IV ##STR3## or β-alkoxy-substitutedphthalocyanines of the formulae Ia-IVa ##STR4## where Me is a divalentmetal atom or a divalent oxo metal,

R₁ is a linear or branched C₁ --C₁₆ alkyl, C₃ --C₁₆ alkenyl or C₃ --C₁₆alkynyl radical, which is unsubstituted or substituted by C₁ --C₁₂alkoxy, --CN, NO₂, halogen, --OH, phenyl, cyanophenyl, nitrophenyl,halophenyl, hydroxyphenyl or (C₁ --C₁₂ alkoxy)phenyl,

wherein the isomers of the formula II or IIa and of the formula III orIIIa make up at least 80% of the total mixture, and the isomers of theformula I or Ia and of the formula IV or IVa make up at most 20% of thetotal mixture, with the ratio between the compounds of the formula II orIIa and the compounds of the formula III or IIIa being from 0.3 to 3.0:1.

For the purposes of the present invention, percentage data are % byweight.

Preference is given to isomer mixtures in which the isomers of theformula II or IIa and of the formula III or IIIa make up at least 90% ofthe total mixture, and the isomers of the formula I or Ia and of theformula IV or IVa make up at most 10% of the total mixture.

Particular preference is given to isomer mixtures in which the isomersof the formula II or IIa and of the formula III or IIIa make up at least95% of the total mixture, and the isomers of the formula I or la and ofthe formula IV or IVa make up at most 5% of the total mixture.

In particular, preference is given to isomer mixtures in which the ratiobetween the compounds of the formula II or IIa and the compounds of theformula III or IIIa is from 0.5 to 2.0:1.

Examples of linear or branched C₁ --C₁₆ alkyl radicals are methyl, ethyland the various positional isomers of propyl, butyl, pentyl, hexyl,heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl,pentadecyl and hexadecyl.

Preference is given to C₄ --C₁₂ alkyl radicals.

Examples of C₃ --C₁ 6alkenyl radicals are propenyl, butenyl, pentenyl,hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl,tridecenyl, tetradecenyl, pentadecenyl and hexadecenyl with theirvarious positional isomers.

Preference is given to C₄ --C₁₂ alkenyl radicals.

Examples of C₃ --C₁₆ alkynyl radicals are propynyl, butynyl, pentynyl,hexynyl, heptynyl, octynyl, nonynyl, decynyl, undecynyl, dodecynyl,tridecynyl, tetradecynyl, pentadecynyl and hexadecynyl with theirvarious positional isomers.

Preference is given to C₄ --C₁₂ alkynyl radicals.

The alkyl, alkenyl and alkynyl radicals are preferably branched.

Halogen is, for example, fluorine, bromine, chlorine or iodine.

Examples of C₁ --C₁₂ alkoxy radicals are methoxy, ethoxy and the variouspositional isomers of propoxy, butoxy, pentoxy, hexyloxy, heptyloxy,octyloxy, nonyloxy, decyloxy, undecyloxy and dodecyloxy.

Preference is given to C₁ --C8alkoxy.

Suitable divalent metal atoms or oxo metals are a multiplicity ofmetals, as described, for example, by F. H. Moser, A. L. Thomas, in ThePhthalocyanines, CRC Press 1983.

The divalent metal atom or oxo metal is preferably Cu(II), Zn(II),Fe(II), Ni(II), Ru(II), Rh(II), Pd(II), Pt(II), Mn(II), Mg(II), Be(II),Ca(II), Ba(II), Cd(II), Hg(II), Sn(II), Co(II), Pb(II) or VO, MnO, TiO.

Particular preference is given to the divalent metal atoms Zn(II),Sn(II), Cu(II), Ni(II), Co(II), Pb(II) or Pd(II).

Very particular preference is given to the divalent metal atoms Pd(II),Cu(II) or Ni(II), in particular Cu(II) and especially Pd(II).

In a preferred sub-group, R₁ is a linear or branched C₁ --C₁₆ alkylradical which is unsubstituted or substituted by C₁ --C₁₂ alkoxy, --CN,NO₂, halogen, --OH, phenyl, cyanophenyl, nitrophenyl, halophenyl,hydroxyphenyl or (C₁ --C₁₂ alkoxy)phenyl.

In a particularly preferred sub-group, R₁ is a linear or branched C₄--C₁₂ alkyl radical which is unsubstituted or substituted by C₁ --C₁₂alkoxy, --CN, NO₂, halogen, --OH, phenyl, cyanophenyl, nitrophenyl,halophenyl, hydroxyphenyl or (C₁ --C₁₂ alkoxy)phenyl.

R₁ is very particularly preferably an unsubstituted linear or branchedC₄ --C₁₂ alkyl radical, in particular a branched C₄ --C₁₂ alkyl radical,for example 2,4-dimethyl-3-pentoxy.

The substitution can take place either in the β-position or in theα-position, but the --OR₁ substituent is preferably in the α-position.

In the case of α-substitution, the 4 positional isomers of the formulaeI to IV can form during the reaction. Preference is given to isomermixtures of compounds of the formulae I to IV.

The individual positional isomers differ through their solubility inorganic solvents, in particular in aliphatic hydrocarbons. The highlysymmetrical isomers of the formulae I and IV have the lowest solubility.

In the case of β-substitution, the corresponding 4 isomers of theformulae Ia to IVa can arise; within this series, the isomers of theformulae Ia and IVa likewise have the lowest solubilities.

The invention furthermore relates to a process for the preparation of amixture of isomeric compounds of the formulae I to IV or Ia to IVa inwhich the isomers of the formula II or IIa and of the formula III orIIIa make up at least 80% of the total mixture and the isomers of theformula I or Ia and of the formula IV or IVa make up at most 20% of thetotal mixture, and the ratio between the compounds of the formula II orIIa and the compounds of the formula III or IIIa is from 0.3 to 3.0:1,by reacting compounds of the formula V ##STR5## in the presence of ametal salt and a Lewis acid, where R₁ is as defined above,

which comprises carrying out the reaction in the presence ofnitrobenzene, nitrotoluene or nitroxylene and an at least equimolaramount of urea, based on the compounds of the formula V.

Preference is given to metal salts in which the anion is derived from amonobasic or dibasic inorganic acid, a C₁ --C₁₂ carboxylic acid or a C₅--C₁₂ --β-diketone.

Suitable inorganic acids are in particular HCl, HBr, H₂ SO₄, HNO₃ andHClO₄. Examples of suitable C₁ --C₁₂ carboxylic acids are formic acid,acetic acid, propionic acid, the various isomers of butyric acid,valeric acid and caproic acid. Examples of suitable C₅ --C₁₂--β-diketones are acetylacetone, hexane-2,4-dione, heptane-3,5-dione,heptane-2,4-dione, and the various positional isomers of octane-,nonane-, decane-, undecane- and dodecane-β-diones.

The metal salt is particularly preferably Pd(II)Cl₂, Cu(II)Cl₂,Zn(II)Cl₂, Ni(II)Cl₂, Cu(II) acetylacetonate or V(III) acetylacetonate.

Very particular preference is given to Pd(II)Cl₂, Cu(II)Cl₂ andNi(II)Cl₂.

The reaction is preferably carried out at a molar ratio between thecompounds of the formula V and urea of from 1:1 to 1:20, particularlypreferably in a molar ratio of from 1:1 to 1:10.

The weight ratio between urea and nitrobenzene, nitrotoluene ornitroxylene is preferably from 1:1 to 1:50, particularly preferably from1:5 to 1:20.

The process is preferably carried out at a temperature of from 130° to250° C., particularly preferably at a temperature of from 130° to 190°C.

The pressure conditions are not crucial per se, but the process ispreferably carried out at a pressure of from 1·10⁵ to 20·10⁵ Pa.

The reaction time may differ depending on the metal atom; it ispreferably from 0.5 to 24 hours.

A large number of Lewis acids are known to the person skilled in theart, for example AlCl₃, AlBr₃, BF₃, BCl₃, SbCl₃, SbBr₃, AsBr₃, AsCl₃,ZnCl₂, ZnBr₂, SnCl₂, SnBr₂, ammonium molybdate and ammonium molybdatetetrahydrate, and others.

The Lewis acid is preferably ammonium molybdate or ammonium molybdatetetrahydrate.

The Lewis acid is preferably employed in an amount of from 0.1 to 5% byweight, based on the compounds of the formula V.

The invention also relates to a material for the optical recording andstorage of information in which a layer of a phthalocyanine of theformula I-IV or of the formula Ia-IVa prepared in accordance with theinvention has been applied as recording material to a transparent,dielectric carrier. A reflection layer and protective coating mayadditionally have been applied to the material. The embodimentsdescribed in EP-A-0 546 994, for example, also apply.

The novel information-containing material represents, in particular, anoptical information material of the WORM type. It can be used, forexample, as a playable compact disc (CD), as a storage material forcomputers or as an identity and security card.

The invention therefore furthermore relates to the use of the isomermixtures of claim 1 in optical storage media for information recordingin WORM systems.

The examples below illustrate the invention.

EXAMPLE 1

50 g (206 mmol) of 3-(2,4-dimethyl-3-pentoxy)phthalodinitrile, 9.1 g(51.7 mmol) of anhydrous palladium chloride, 24.8 g (413 mmol) of ureaand 1 g (2% by weight) of ammonium molybdate are introduced into 200 mlof nitrobenzene, and the mixture is heated to 160° C. with stirringunder an argon atmosphere. The mixture is subsequently stirred at thistemperature for 4 hours, then cooled to RT, diluted with toluene andfiltered through a filter aid. The filtrate is evaporated to dryness at100° C./10⁻¹ mbar. The residue is taken up in 400 ml of toluene, andfiltered through 500 g of silica gel using toluene as eluent. Thetoluene phase is evaporated to 250 ml and subsequently added dropwise to1.51 of methanol. The precipitate is filtered off and washed twice with100 ml of methanol, then dried at 60° C./165 mbar for 12 hours, giving35.2 g (59% of theory) of a greenish-blue solid having a λ_(max) of 702nm (ε=215 190 I ·mol⁻¹ ·cm⁻¹) in N-methylpyrrolidone (NMP). The NMRshows that the isomers I, II and III are present in a ratio of 5:53:42.

EXAMPLE 2

5.0 g (20.6 mmol) of 3-(2,4-dimethyl-3-pentoxy)phthalodinitrile, 1.35 g(5.15 mmol) of copper acetylacetonate, 2.5 g (41.3 mmol) of urea and 0.1g (2% by weight) of ammonium molybdate are introduced into 20 ml ofnitrobenzene, and the mixture is heated to 160° C. with stirring underan argon atmosphere and subsequently stirred at this temperature for 4hours. The mixture is subsequently cooled to RT, diluted with tolueneand filtered through a filter aid. The filtrate is evaporated to drynessat 100° C./10⁻¹ mbar. The residue is taken up in methylene chloride, 100g of silica gel are added, the solvent is evaporated, the mixture isthen transferred onto a glass suction filter, and the product is elutedwith hexane/ethyl acetate 25:1. The filtrate is evaporated, the residueis dissolved in 30 ml of toluene, and the solution is added dropwise to400 ml of methanol. The precipitate is filtered off, washed twice with10 ml of methanol and dried at 60° C./125 mmHg for 12 hours, giving 2.0g (38% of theory) of a greenish-blue solid having a λ_(max) (NMP) of 713nm (ε=220 140 l ·mol⁻¹ ·cm⁻¹).

EXAMPLE 3

100.0 g (0.41 mol) of 3-(2,4-dimethyl-3-pentoxy)phthalodinitrile, 14.0 g(0,1 mol) of copper(II) chloride, 49.6 g (0.82 mol) of urea and 2.0 g(2% by weight) of ammonium molybdate are introduced into 410 ml ofnitrobenzene, and the mixture is heated to 160° C. with stirring underan argon atmosphere and subsequently stirred at this temperature for 5hours. The mixture is subsequently cooled to RT, diluted with tolueneand filtered through a filter aid. The filtrate is evaporated to drynessat 10° C./10⁻¹ mmHg. The residue is dissolved in 1 l of toluene andfiltered through 600 g of silica gel with toluene as eluent. Thefiltrate is evaporated, and the residue is stirred in 1.5 l of methanol,filtered, washed with methanol and dried overnight at 60° C./165 mbar,giving 99.5 g (94% of theory) of a greenish-blue solid having a λ_(max)(NMP) of 712 nm (ε=197 680 l·mol⁻¹ ·cm⁻¹). Thin layer chromatographyshows that the isomers I, II and III are present in a ratio of 5:33:62.

EXAMPLE 4

5 g (20.6 mmol) of 3-(2,4-dimethyl-3-pentoxy)phthalodinitrile, 1.79 g(5,15 mmol) of vanadium(III) acetylacetonate, 2.5 g (41.3 mmol) of ureaand 100 mg (2% by weight) of ammonium molybdate are introduced into 20ml of nitrobenzene, and the mixture is heated to 150° C. with stirringunder an argon atmosphere and stirred at this temperature for 4 hours.The mixture is subsequently cooled to RT, diluted with toluene andfiltered through a filter aid. The filtrate is evaporated to dryness andfiltered through 150 g of silica gel with hexane/ethyl acetate=25:1. Thegreen fraction is evaporated, taken up in 15 ml of toluene and addeddropwise to 300 ml of methanol. The precipitate is filtered off anddried overnight at 60° C./165 mbar, giving 1.9 g (36.1% of theory) of agreen solid having a λ_(max) (NMP) of 743 nm (ε=180 860 l·mol⁻¹ ·cm⁻¹)and a vanadium content of 4.52%.

EXAMPLE 5

15 g (61.9 mmol) of 4-(2,4-dimethyl-3-pentoxy)phthalodinitrile, 2.74 g(15.48 mmol) of palladium(II) chloride, 7.43 g (123.8 mmol) of urea and300 mg (2% by weight) of ammonium molybdate are introduced into 60 ml ofnitrobenzene, and the mixture is heated to 160° C. with stirring underan argon atmosphere and stirred at this temperature for 24 hours. Themixture is then cooled to RT, diluted with toluene and filtered througha filter aid. The filtrate is evaporated to dryness and filtered through200 g of silica gel with toluene. The blue fraction is evaporated, theresidue is taken up in 50 ml of toluene, and the solution is addeddropwise to 700 ml of methanol. The precipitate is filtered off anddried overnight at 60° C./165 mbar, giving 8.0 g (48.0% of theory) of ablue solid having a λ_(max) (NMP) of 675 nm.

COMPARATIVE EXAMPLE 1

20 g of urea, 5.0 g (20.6 mmol) of 3-(2,4-dimethyl-3-pentoxy)-phthalodinitrile, 0 .9 1 g (5.2 mmol) of anhydrous palladium chlorideand 100 mg of ammonium molybdate are heated at 160° C. for 7 hours withstirring under an argon atmosphere. Initially, a brown suspension forms,which solidifies during the course of the reaction. The mixture issubsequently cooled, the solid is taken up in methylene chloride, andthe solution is filtered. 80 g of silica gel are then added, and thesolvent is evaporated.

The loaded silica gel is transferred onto a glass suction filter, andthe product is eluted using 1 l of hexane/ethyl acetate 25:1. The eluateis evaporated, the residue is dissolved in 15 ml of toluene and thesolution is added dropwise to 300 ml of methanol. The precipitate isfiltered off and washed twice with 10 ml of methanol, then dried for 12hours at 60° C./165 mbar, giving 1.2 g (21.6% of theory) of a blue-greenpowder having a λ_(max) (NMP) of 702 nm (ε=195 780 l·mol⁻¹ ·cm⁻¹).

COMPARATIVE EXAMPLE 2

5.0 g (20.6 mmol) of 3-(2,4-dimethyl-3-pentoxy)phthalodinitrile, 1.09 g(6.2 mmol) of anhydrous palladium chloride and 100 mg of ammoniummolybdate are introduced into 20 ml of nitrobenzene, and the mixture isheated at 160° C. for 4 hours with stirring under an argon atmosphere.The mixture is subsequently cooled and filtered, the solid is washedwell with toluene and the filtrate is evaporated to dryness in a highvacuum at 110° C. The crude product is dissolved in methylene chloride,70 g of silica gel are added, and the solvent is evaporated. The loadedsilica gel is transferred onto a glass suction filter, an d the productis eluted using hexane/ethyl acetate 25:1. The eluate is evaporated, andthe residue is dried for 12 hours at 60° C./165 mbar, giving 0.80 g(14%) of a blue-green powder having a λ_(max) (NMP) of 702 nm (ε=225 080l·mol⁻¹ ·cm⁻¹).

What is claimed is:
 1. A process for the preparation of a mixture ofisomeric α-alkoxy-substituted phthalocyanines of the formulae I-IV##STR6## or β-alkoxy-substituted phthalocyanines of the formulae Ia-IVa##STR7## where Me is a divalent metal atom or a divalent oxo metal,andR₁ is a linear or branched C₁ --C₁₆ alkyl, C₃ --C₁₆ alkenyl or C₃--C₁₆ alkynyl radical, which is unsubstituted or substituted by C₁ --C₁₂alkoxy, --CN, NO₂, halogen, --OH, phenyl, cyanophenyl, nitrophenyl,halophenyl, hydroxyphenyl or (C₁ --C₁₂ alkoxy)phenyl, and wherein theisomers of the formula II or IIa and of the formula III or IIIa make upat least 80% of the total mixture, and the isomers of the formula I orIa and of the formula IV or IVa make up at most 20% of the totalmixture, with the ratio between the compound of the formula II or IIaand the compounds of the formula III or IIIa being from 0.3 to 3.0:1, byreacting compound of the formula V ##STR8## in the presence of a metalsalt and a Lewis acid, where R₁ is as defined above, which comprisescarrying out the reaction in the presence of nitrobenzene, nitrotolueneor nitroxylene and an at least equimolar amount of urea, based on thecompounds of the formula V.
 2. A process according to claim 1, whereinthe metal salt contains the anion of a monobasic or dibasic mineralacid, C₁ --C₁₂ carboxylic acid or C₅ --C₁₂ β-diketone.
 3. A processaccording to claim 1, wherein the metal salt is Pd(II)Cl₂, Cu(II)Cl₂,Zn(II)Cl₂, Ni(II)Cl₂, Cu(II) acetylacetonate or V(III) acetylacetonate.4. A process according to claim 1, wherein the metal salt is Pd(II)Cl₂,Cu(II)Cl₂ or Ni(II)Cl₂.
 5. A process according to claim 1, wherein thereaction is carried out at a molar ratio between the compounds of theformula V and urea of from 1:1 to 1:20.
 6. A process according to claim1, wherein the weight ratio between urea and nitrobenzene, nitrotolueneor nitroxylene is from 1:11 to 1:50.
 7. A process according to claim 1,wherein the weight ratio between urea and nitrobenzene, nitrotoluene ornitroxylene is from 1:5 to 1:20.
 8. A process according to claim 1,which is carried out at a temperature of from 130° to 250° C.
 9. Aprocess according to claim 1, which is carried out at a temperature offrom 130° to 190° C.
 10. A process according to claim 1, which iscarried out at a pressure of from 1·10⁵ to 20·10⁵ Pa.
 11. A processaccording to claim 1, wherein the Lewis acid is ammonium molybdate orammonium molybdate tetrahydrate.
 12. A process according to claim 1,wherein the Lewis acid is present in an amount of from 0.1 to 5% byweight, based on the compounds of the formula V.
 13. A material for theoptical recording and storage of information in which at least one layerof a mixture of isomeric α-alkoxy-substituted phthalocyanines of theformulae I-IV ##STR9## or βalkoxy-substituted phthalocyanines of theformulae Ia-IVa ##STR10## where Me is a divalent metal atom or adivalent oxo metal,R₁ is a linear or branched C₁ --C₁₆ alkyl or C₃ --C₁₆aldenyl or C₃ --C₁₆ aldynyl radical, which is unsubstituted orsubstituted by C₁ --C₁₂ alkoxy, --CN, NO₂, halogen, --OH, phenyl,cyanophenyl, nitrophenyl, halophenyl, hydroxyphenyl or (C₁ --C₁₂alkoxy)phenyl. wherein the isomers of the formula II or IIa and of theformula III or IIIa make up at least 80% of the total mixture, and theisomers of the formula I or Ia and of the formula IV or IVa make up atmost 20% of the total mixture, with the ratio between the compounds ofthe formula II or IIa and the compounds of the formula III or IIIa beingfrom 0.3 to 3.0:1, has been applied to a transparent, dielectriccarrier.
 14. A material for optical recording and storage of informationaccording to claim 13 which is of the WORM (write once read many) type.